body,html{
  margin:0;padding:0;
  text-align:center;
  font-family:"微软雅黑";
}
.show{
  width:700px;height:500px;
  border:solid 1px;
  border-radius:20px;
  margin-left:0;margin-right:0;margin:auto;margin-top:20px;
  padding-left:30px;padding-top:30px;
  text-align:left;font-size:18px;
  background-color:#ccc;
}
#city{
  width:100px;height:40px;
  font-size:20px;
}